Minor changes

Add RS485 and RS232

README.md

@@ -4,6 +4,12 @@ This roadmap is designed to assist beginners aspiring to build a career as an Em
 
 Becoming an embedded engineer requires a broad understanding of both software and hardware. If you are starting on this journey, you must be highly motivated and passionate to pursue this path. The field of embedded systems demands a solid understanding of hardware functionality. But, as the well-known saying goes, "Hardware is hard!". So, patience and passion are the essential qualities that will help you overcome the various challenges encountered along this journey.
 
+## What is an Embedded System?
+
+An [***embedded system***](https://www.analog.com/en/design-center/glossary/embedded-system.html) is a system in which the **computer** (generally a microcontroller or microprocessor) is included as an integral part of the system.
+
+Often, the computer is relatively **invisible to the user**, without obvious applications, files, or operating systems. Examples of products with invisible embedded systems are the controller that runs a microwave oven or the engine control system of a modern automobile.
+
 ## Roadmap
 
 ![Embedded Systems Engineering Roadmap](https://github.com/m3y54m/Embedded-Engineering-Roadmap/releases/latest/download/Embedded-Engineering-Roadmap.png)
@@ -16,7 +22,7 @@ Becoming an embedded engineer requires a broad understanding of both software an
 
 - [Searching is Your Super Power!](https://www.google.com)
 
-#### 🎥 Courses and Youtube Channels
+#### 🎥 Courses and YouTube Contents
 
 - [Fastbit Embedded Brain Academy](https://fastbitlab.com/)
 - [Quantum Leaps, LLC (YouTube Channel)](https://www.youtube.com/@StateMachineCOM)
@@ -24,6 +30,8 @@ Becoming an embedded engineer requires a broad understanding of both software an
 - [element14 presents (YouTube Channel)](https://www.youtube.com/@element14presents)
 - [Ben Eater (YouTube Channel)](https://www.youtube.com/@BenEater)
 - [Phil’s Lab (YouTube Channel)](https://www.youtube.com/@PhilsLab)
+- [Electronic Basics - GreatScott! (YouTube Playlist)](https://youtube.com/playlist?list=PLAROrg3NQn7cyu01HpOv5BWo217XWBZu0)
+- [Embedded Systems - Jacob Sorber (YouTube Playlist)](https://www.youtube.com/playlist?list=PL9IEJIKnBJjEcPAz6fss-Hx0TLytCOMVC)
 
 #### 📚 Books
 
@@ -33,11 +41,11 @@ Becoming an embedded engineer requires a broad understanding of both software an
 #### 🤡 Simulation
 
 - [Wokwi - Online ESP32, STM32, Arduino Simulator](https://wokwi.com/)
-- [QEMU](https://www.qemu.org/)
+- [QEMU - open-source freeware for emulating hardware and devices](https://www.qemu.org/)
 
 #### 🕹️ Arduino
 
-If you do not have any background in programming embedded systems, Arduino boards and libraries are the best choice for you to start and learn the basics. Just keep in mind that most of the Arduino libraries are developed only for learning purposes and are not are not optimized to be used in industry. If you want to become a professional embedded developer, you should have the ability to utilize industry-compliant APIs and frameworks provided and qualified by microcontroller vendors such as STM32Cube for STM32 microcontrollers or ESP-IDF for Espressif microcontrollers.
+If you do not have any background in programming embedded systems, Arduino boards and libraries are the best choice for you to start and learn the basics. Just keep in mind that most of the Arduino libraries are developed only for learning purposes and are not are not optimized to be used in industry. Additionally, the Arduino takes care of most of the low-level operations and manipulation of registers that you, as an embedded engineer, should be able to handle yourself. If you want to become a professional embedded developer, you must be able to effectively use industry-standard APIs and frameworks provided and approved by microcontroller vendors. For example, CMSIS for ARM Cortex, STM32Cube for STM32, ESP-IDF for Espressif microcontrollers, etc.
 
 - [Getting Started with Arduino](https://docs.arduino.cc/learn/starting-guide/getting-started-arduino)
 - [New Arduino Tutorials](https://youtube.com/playlist?list=PLGs0VKk2DiYw-L-RibttcvK-WBZm8WLEP)
@@ -53,23 +61,41 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 #### 👨‍🏫 Educational Websites
 
 - [DeepBlueMbedded](https://deepbluembedded.com/)
+- [Interrupt Blog by Memfault](https://interrupt.memfault.com/blog/)
 - [Microchip University](https://mu.microchip.com/)
 - [SparkFun Learn: Learn at SparkFun Electronics](https://learn.sparkfun.com/)
 - [Adafruit Learning System](https://learn.adafruit.com/)
 - [Random Nerd Tutorials | Learn ESP32, ESP8266, Arduino, and Raspberry Pi](https://randomnerdtutorials.com/)
 - [ControllersTech](https://controllerstech.com/)
 
+#### 🗺️ Other Useful Roadmaps
+
+- [Embedded Systems Skill Tree](https://github.com/sjpiper145/MakerSkillTree/tree/main/Embedded%20Systems%20Skill%20Tree)
+- [PCB Design Skill Tree](https://github.com/sjpiper145/MakerSkillTree/tree/main/PCB%20Design%20Skill%20Tree)
+
 #### ⚒️ Projects
 
 - [STM32 Firmware](https://youtube.com/playlist?list=PLXSyc11qLa1a4Tqbz228dPZfMrs-KRpzA)
 - [Udemy – STM32 : Internet Of Things with 4G LTE Modem - Hardware](https://www.udemy.com/course/stm32-internet-of-things-with-4g-lte-modem-hardware/)
 
-> **Note:** It is not necessary to read or watch all of the following materials,
-> but it is important to study enough to have at least a basic understanding of each topic.
-> Of course, the more you study and practice, the deeper and wider your knowledge will become.
-> This will ultimately improve your skills as an engineer.
-> 
-> Some the resources mentioned here will only be used as references. Refer to them only when you need them.
+#### 😈 Hardware Hacking
+
+- [Hardware Hacking Tutorial](https://www.youtube.com/playlist?list=PLoFdAHrZtKkhcd9k8ZcR4th8Q8PNOx7iU)
+- [The Hardware Hacking Handbook: Breaking Embedded Security with Hardware Attacks - Jasper van Woudenberg, Colin O'Flynn](https://a.co/d/gUIytFX)
+
+_________________
+
+**Note:** It is not necessary to read or watch all of the following materials, but it is important to study enough to have a basic understanding of each topic. Of course, the more you study and practice, the greater your knowledge will become, ultimately enhancing your abilities as an engineer.
+
+Some of the resources mentioned here will just be used as references. Refer to them only when you need them.
+_________________
+
+### Soft Skills
+
+- [Soft Skills For Embedded Systems Software Developers](https://www.embeddedrelated.com/showarticle/1470.php)
+- [10 Skills Every Embedded Engineer Should Have](https://medium.com/@lanceharvieruntime/10-skills-every-embedded-engineer-should-have-dcb867095b91)
+
+_________________
 
 ### Electronics Fundamentals
 
@@ -88,6 +114,7 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 
 #### Electronic Components
 
+- [Here’s a Quick Way to Know about Major Electronic Components](https://www.elprocus.com/major-electronic-components/)
 - [Encyclopedia of Electronic Components - Charles Platt](https://a.co/d/83cSiU7)
 
 #### Digital Circuits & Logic Design
@@ -101,6 +128,8 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [Digital Design and Computer Architecture: ARM Edition -  Sarah Harris, David Harris](https://a.co/d/4otoVvI)
 - [Embedded Systems Architecture - Tammy Noergaard](https://www.oreilly.com/library/view/embedded-systems-architecture/9780123821966/)
 
+_________________
+
 ### Using Test Equipment
 
 #### Multimeter
@@ -117,6 +146,9 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [What’s an OSCILLOSCOPE?](https://youtu.be/DgYGRtkd9Vs)
 - [How to Use an Oscilloscope](https://youtu.be/u4zyptPLlJI)
 - [How to use an oscilloscope / What is an oscilloscope / Oscilloscope tutorial](https://youtu.be/CzY2abWCVTY)
+- [Understanding EMI Debugging with Oscilloscopes](https://www.youtube.com/watch?v=x1rn5YNLmVw)
+
+_________________
 
 ### Prototyping Skills
 
@@ -152,8 +184,11 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [How to Solder QFN MLF Package by Hand (Using a Hot Air Rework Station) | Digi-Key Electronics](https://youtu.be/X3Rc1s6EpSI)
 - [From Solderless Breadboard to Soldered Circuit - Electronics with Becky Stern | Digi-Key Electronics](https://www.youtube.com/watch?v=F9Krq7seV1g)
 
+_________________
+
 ### FPGA Design
 
+- [FPGA vs. Microcontroller: How to choose the right one for your project](https://www.youtube.com/watch?v=jblpHUCPQYs)
 - [Introduction to FPGA](https://youtube.com/playlist?list=PLEBQazB0HUyT1WmMONxRZn9NmQ_9CIKhb)
 - [FPGA Fundamentals](https://nandland.com/fpga-101/)
 - [Udemy – FPGA Embedded Design, Part 1 - Verilog](https://www.udemy.com/course/fpga-embedded-design-verilog/)
@@ -161,6 +196,8 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [Udemy – FPGA Embedded Design, Part 3 - EDA Tools](https://www.udemy.com/course/fpga-embedded-design-eda-tools/)
 - [Udemy – FPGA Embedded Design, Part 4 - Microprocessor Design](https://www.udemy.com/course/fpga-embedded-design-cpu/)
 
+_________________
+
 ### Software Development Life Cycle (SDLC) Models
 
 - [What is the software development life cycle?](https://www.coderus.com/the-software-development-lifecycle/)
@@ -170,12 +207,15 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [What Is Scrum: A Guide to the Most Popular Agile Framework](https://www.scrumalliance.org/about-scrum)
 - [What Is the V-Model in Software Development?](https://builtin.com/software-engineering-perspectives/v-model)
 
+_________________
+
 ### Programming Fundamentals
 
 #### Algorithms & Data Structures
 
 - [Grokking Algorithms - Aditya Y. Bhargava ](https://www.manning.com/books/grokking-algorithms)
 - [Introduction to Algorithms - Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest and Clifford Stein](http://mitpress.mit.edu/9780262367509/introduction-to-algorithms/)
+- [Collection of various algorithms in mathematics, machine learning, computer science, physics, etc implemented in C for educational purposes](https://github.com/TheAlgorithms/C)
 - [Udemy – Embedded Systems State Machines & Data Structures](https://www.udemy.com/course/embedded-systems-state-machines-data-structures-like-a-pro/)
 - [Data Structures in C](https://www.sanfoundry.com/c-programming-examples-data-structures/)
 - [Data Structures - Full Course Using C and C++](https://www.youtube.com/watch?v=B31LgI4Y4DQ)
@@ -196,6 +236,8 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [Dynamic Memory Allocation | C Programming Tutorial](https://www.youtube.com/watch?v=R0qIYWo8igs)
 - [What is Memory Leak in C/C++? How can we avoid?](https://aticleworld.com/what-is-memory-leak-in-c-c-how-can-we-avoid/)
 
+_________________
+
 ### Programming Languages 
 
 #### C
@@ -227,9 +269,12 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 #### Rust
 
 - [The Embedded Rust Book](https://docs.rust-embedded.org/book/)
+- [The Future of Programming: Rust](https://www.youtube.com/playlist?list=PLc7W4b0WHTAUAEAguiqpNa5H0QqXJIJI6)
 - [Community Rust support projects for STM32 microcontrollers](https://github.com/stm32-rs)
 - [Rust on ESP Community](https://github.com/esp-rs)
 
+_________________
+
 ### Build System
 
 #### GCC & Make
@@ -249,6 +294,8 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 
 - [Introduction to Docker for the Embedded Developer](https://www.youtube.com/watch?v=Fz7ou-VBk-w)
 
+_________________
+
 ### Version Control
 
 #### Git
@@ -260,11 +307,14 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 
 - [Apache® Subversion®](https://subversion.apache.org/)
 
+_________________
+
 ### Microcontrollers
 
 - [Make: AVR Programming - Elliot Williams](https://www.oreilly.com/library/view/make-avr-programming/9781449356484/)
 - [Mastering STM32 - Carmine Noviello](https://leanpub.com/mastering-stm32-2nd)
 - [Getting Started with STM32 and Nucleo](https://youtube.com/playlist?list=PLEBQazB0HUyRYuzfi4clXsKUSgorErmBv)
+- [Bare Metal Embedded Programming: Theory and Practice Using STM32](https://www.youtube.com/playlist?list=PL4cGeWgaBTe155QQSQ72DksLIjBn5Jn2Z)
 - [Beginning STM32: Developing with FreeRTOS, libopencm3 and GCC - Warren Gay](https://link.springer.com/book/10.1007/978-1-4842-3624-6)
 - [Intro to Raspberry Pi Pico and RP2040](https://www.youtube.com/playlist?list=PLEBQazB0HUyQO6rJxKr2umPCgmfAU-cqR)
 - [Udemy – Microcontroller Embedded C Programming: Absolute Beginners](https://www.udemy.com/course/microcontroller-embedded-c-programming/)
@@ -335,10 +385,13 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [Udemy – Functional Safety According to ISO 26262 - Crash Course](https://www.udemy.com/course/iso-26262-crash-course/)
 - [A Guide to MISRA C Coding Standards - MISRA C and MISRA C++](https://www.perforce.com/resources/qac/misra-c-cpp)
 
-### Interfaces & Protocols
+_________________
+
+### Interfaces, Protocols & Communication Technologies
 
 #### Common
 
+- [Understanding Serial Protocols](https://www.youtube.com/watch?v=LEz5UCN3aHA)
 - [PROTOCOLS: UART - I2C - SPI - Serial communications #001](https://www.youtube.com/watch?v=IyGwvGzrqp8)
 
 ##### UART
@@ -347,15 +400,27 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [how does UART work??? (explained clearly)](https://www.youtube.com/watch?v=V6m2skVlsQI)
 - [Basics of UART Communication | UART Frame Structure | RS 232 Basics | Part1](https://www.youtube.com/watch?v=JuvWbRhhpdI)
 - [Understanding UART Communication Programming | UART Peripherals | Part 2](https://www.youtube.com/watch?v=QmjKRwgddxw)
+- [The RS-232 protocol](https://www.youtube.com/watch?v=AHYNxpqKqwo)
 
 ##### I2C
 
+- [Understanding I2C](https://www.youtube.com/watch?v=CAvawEcxoPU)
 - [STM32 I2C SLAVE](https://www.youtube.com/playlist?list=PLfIJKC1ud8gj_P7Qb28aTr0t92uk_vwg0)
 
 ##### SPI
 
+- [Understanding SPI](https://www.youtube.com/watch?v=0nVNwozXsIc)
+- [SPI: The serial peripheral interface](https://www.youtube.com/watch?v=MCi7dCBhVpQ)
 - [Getting Started with STM32 and Nucleo Part 5: How to Use SPI | Digi-Key Electronics](https://www.youtube.com/watch?v=eFKeNPJq50g)
 
+##### 1-Wire
+
+- [1-Wire® Technology Overview](https://www.youtube.com/watch?v=CjH-OztKe00)
+
+#### I2S
+
+- [Building a Digital Music Player with I2S?! What is I2S! EB#45](https://www.youtube.com/watch?v=qNLvoSQCx60)
+
 #### Wireless
 
 - [Bluetooth Low Energy Fundamentals - Nordic Semiconductor](https://academy.nordicsemi.com/courses/bluetooth-low-energy-fundamentals/)
@@ -364,10 +429,43 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 
 #### Industrial
 
+##### Modbus
+
+- [What is Modbus and How does it Work?](https://www.youtube.com/watch?v=txi2p5_OjKU)
+- [How does Modbus Communication Protocol Work?](https://www.youtube.com/watch?v=JBGaInI-TG4)
+- [MODBUS STM32](https://www.youtube.com/playlist?list=PLfIJKC1ud8ggRvaEsMjSEDazoBAnY4MUv)
+
+##### RS485
+
+- [What is RS485 and How it's used in Industrial Control Systems?](https://www.youtube.com/watch?v=3wgKcUDlHuM)
+- [What is RS-485?](https://www.youtube.com/watch?v=bt9Px51eP6s)
+
+##### CoAP & MQTT
+
+- [#144 Internet Protocols: CoAP vs MQTT, Network Sniffing, and preparation for IKEA Tradfri Hacking](https://www.youtube.com/watch?v=pfG8uEDZj5g)
+- [MQTT vs. CoAP | Comparison of IoT Protocols](https://www.youtube.com/watch?v=0CORpVSUQe0)
+- [Simple ESP32 IoT Sensor Node Tutorial: WiFi Enabled MQTT Sensor Data Node](https://www.youtube.com/watch?v=x5A5S0hoyJ0)
+- [Cellular IoT Fundamentals - Nordic Semiconductor](https://academy.nordicsemi.com/courses/cellular-iot-fundamentals/)
+
 #### High-Speed
 
+##### Ethernet
+
+- [How the Ethernet Protocol Works – A Complete Guide](https://www.freecodecamp.org/news/the-complete-guide-to-the-ethernet-protocol/)
+- [What is an Ethernet PHY?](https://www.youtube.com/watch?v=JH3cMYErmKI)
+- [The Data Link Layer, MAC Addressing, and the Ethernet Frame](https://youtu.be/_b4dXKB8Pt8)
+
+##### USB
+
+- [Training - USB 101 - Introduction to USB](https://www.youtube.com/watch?v=5S6ZPmtPzRA)
+- [How does a USB keyboard work?](https://youtu.be/wdgULBpRoXk)
+- [How does USB device discovery work?](https://www.youtube.com/watch?v=N0O5Uwc3C0o)
+- [MOOC - STM32 USB training](https://www.youtube.com/playlist?list=PLnMKNibPkDnFFRBVD206EfnnHhQZI4Hxa)
+
 #### Automotive
 
+##### CAN
+
 - [CAN Bus: Serial Communication - How It Works?](https://www.youtube.com/watch?v=JZSCzRT9TTo&t=21s)
 - [CAN Bus: A Beginners Guide Part 1](https://www.youtube.com/watch?v=YBrU_eZM110)
 - [CAN Bus: A Beginners Guide Part 2](https://www.youtube.com/watch?v=z5CVljiLhvc)
@@ -375,24 +473,52 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 
 #### Network
 
+- [Networking Fundamentals](https://www.youtube.com/playlist?list=PLIFyRwBY_4bRLmKfP1KnZA6rZbRHtxmXi)
+- [TCP vs UDP - Explaining Facts and Debunking Myths - TCP Masterclass](https://www.youtube.com/watch?v=jE_FcgpQ7Co)
+- [TCP - 12 simple ideas to explain the Transmission Control Protocol](https://www.youtube.com/watch?v=JFch3ctY6nE)
+- [UDP doesn't suck! It's the BEST L4 protocol for THESE types of applications...](https://www.youtube.com/watch?v=LaDRWycC7Iw)
+- [Networking tutorial](https://www.youtube.com/playlist?list=PLowKtXNTBypH19whXTVoG3oKSuOcw_XeW)
 - [Hands-On Network Programming with C - Lewis Van Winkle](https://www.amazon.com/exec/obidos/ASIN/1789349869/aoeu-20)
 
 #### Cellular
 
+##### GSM / LTE
+
+- [STM32 : Internet Of Things With 4G LTE Modem](https://www.youtube.com/playlist?list=PL2_RO8p04imYY5JOrCDT7V0hnzkgyExRe)
+
+##### LTE-M & NB-IoT
+
 - [Cellular IoT Fundamentals - Nordic Semiconductor](https://academy.nordicsemi.com/courses/cellular-iot-fundamentals/)
 
+_________________
+
 ### Memories
 
+- [Memory Options for Embedded Systems: How to Select the Right Memory Configuration](https://www.qt.io/embedded-development-talk/memory-options-for-embedded-systems-how-to-select-the-right-memory-configuration)
+
 #### NOR / NAND Flash
 
+- [QSPI in STM32 || Write and Read || N25Q](https://www.youtube.com/watch?v=xIfh_uYy-OU)
+- [QSPI in STM32 || Boot from EXT Memory || XIP || N25Q](https://www.youtube.com/watch?v=gAyuF20ok8c)
+- [Flash Memory in Embedded Linux Systems](https://www.youtube.com/watch?v=hdwMvwJIV-Y)
+
 #### eMMC
 
+- [What is a eMMC? Intro, Comparing to Other Storage, and Upgrading. SSD, M.2](https://www.youtube.com/watch?v=vGatKmqYxEA)
+
 #### EEPROM
 
 - [Using EEPROM with Arduino - Internal & External](https://www.youtube.com/watch?v=ShqvATqXA7g)
 
 #### SRAM / DRAM
 
+- [SRAM vs DRAM: Difference Between SRAM & DRAM Explained](https://www.enterprisestorageforum.com/hardware/sram-vs-dram/)
+- [What is SRAM?](https://www.youtube.com/watch?v=kU2SsUUsftA)
+- [SDRAM Hardware & Firmware Tutorial (STM32) - Phil's Lab #80](https://www.youtube.com/watch?v=h28D4AaPSjg)
+- [SDRAM in STM32 || MT48LC4](https://www.youtube.com/watch?v=QnDenqvzwyE)
+
+_________________
+
 ### Sensors & Actuators
 
 - [Getting Started With STM32 and Nucleo Part 2: How to Use I2C to Read Temperature Sensor TMP102](https://www.youtube.com/watch?v=isOekyygpR8)
@@ -400,6 +526,8 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [Interface MPU6050/GY-521 with STM32 || LCD 20x4 || CubeMx || HAL || SW4STM](https://www.youtube.com/watch?v=xxphp9wDnHA)
 - [DC Motor Speed Controller PWM With Potentiometer Using STM32](https://www.youtube.com/watch?v=8QpegVuV_AQ)
 
+_________________
+
 ### Operating Systems
 
 #### Operating System Fundamentals
@@ -408,14 +536,20 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 
 #### Multitasking and Parallel Processing
 
+- [Multitasking vs Multithreading vs Multiprocessing](https://medium.com/codex/multitasking-vs-multithreading-vs-multiprocessing-2b0087c861ae)
+- [Programming with POSIX Threads - David Butenhof](https://a.co/d/9R6DswF)
+- [Parallel Programming and Performance Optimization With OpenMP](https://passlab.github.io/OpenMPProgrammingBook/index.html)
+- [Introduction to OpenMP - Tim Mattson (Intel)](https://youtube.com/playlist?list=PLLX-Q6B8xqZ8n8bwjGdzBJ25X2utwnoEG)
 - [C++ Concurrency in Action - Anthony Williams](https://www.manning.com/books/c-plus-plus-concurrency-in-action)
 
 #### Embedded Linux
 
+- [FreeRTOS vs Linux for Embedded Systems](https://www.bytesnap.com/news-blog/freertos-vs-linux-embedded-systems/)
 - [Introduction to Embedded Linux](https://youtube.com/playlist?list=PLEBQazB0HUyTpoJoZecRK6PpDG31Y7RPB)
 
 ##### Linux Kernel
 
+- [Practical System Programming with C: Pragmatic Example Applications in Linux and Unix-Based Operating Systems - Sri Manikanta Palakollu](https://link.springer.com/book/10.1007/978-1-4842-6321-1)
 - [The Linux Programming Interface - Michael Kerrisk](https://man7.org/tlpi/)
 
 ##### Linux Device Drivers
@@ -445,6 +579,8 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 
 #### Real-Time OS
 
+- [FreeRTOS vs Linux for Embedded Systems](https://www.bytesnap.com/news-blog/freertos-vs-linux-embedded-systems/)
+- [Real-Time Systems Concepts](https://micrium.atlassian.net/wiki/spaces/osiidoc/pages/163855/Real-Time+Systems+Concepts)
 - [RTOS](https://www.youtube.com/playlist?list=PLPW8O6W-1chyrd_Msnn4LD6LBs2slJITs)
 - [Beyond the RTOS](https://www.youtube.com/playlist?list=PLPW8O6W-1chytjkg63-tM7MI0BvGxxPIP)
 
@@ -456,10 +592,12 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [Getting Started With STM32 and Nucleo Part 3: FreeRTOS - How To Run Multiple Threads w/ CMSIS-RTOS](https://www.youtube.com/watch?v=CdpgqpuPSyQ)
 - [Hands-On RTOS with Microcontrollers: Building real-time embedded systems using FreeRTOS, STM32 MCUs, and SEGGER debug tools - Brian Amos](https://a.co/d/11MSPlo)
 - [Beginning STM32: Developing with FreeRTOS, libopencm3 and GCC - Warren Gay](https://link.springer.com/book/10.1007/978-1-4842-3624-6)
+- [SAFE**RTOS** - Safety Critical Real-Time OS](https://www.freertos.org/FreeRTOS-Plus/Safety_Critical_Certified/SafeRTOS.html)
 
 ##### Zephyr
 
 - [Zephyr® Project](https://www.zephyrproject.org/)
+- [Why We Moved from FreeRTOS to Zephyr RTOS](https://www.zephyrproject.org/why-we-moved-from-freertos-to-zephyr-rtos/)
 - [nRF Connect SDK](https://academy.nordicsemi.com/courses/nrf-connect-sdk-fundamentals/)
 - [ESP32 on Zephyr OS](https://www.youtube.com/playlist?list=PLEQVp_6G_y4iFfemAbFsKw6tsGABarTwp)
 
@@ -469,8 +607,6 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [µC/OS-III Documentation](https://micrium.atlassian.net/wiki/spaces/osiiidoc/overview)
 - [µC/OS-III Books](https://weston-embedded.com/micrium-books)
 - [µC/OS-II Documentation](https://micrium.atlassian.net/wiki/spaces/osiidoc/overview)
-- [Microc/Os-II: The Real-Time Kernel - Jean-J Labrosse](https://file.elecfans.com/web1/M00/7F/DD/pIYBAFwnEZGAcwiCAEGrbQfCqmc945.pdf)
-- [Cesium RTOS](https://weston-embedded.com/micrium/overview)
 
 ##### NuttX
 
@@ -494,6 +630,8 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 
 - [VxWorks | Industry Leading RTOS for Embedded Systems](https://www.windriver.com/products/vxworks)
 
+_________________
+
 ### Digital Signal Processing
 
 #### DSP Fundamentals & Filter Design
@@ -529,6 +667,8 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [Getting Started with Simulink](https://youtube.com/playlist?list=PL484BA2AD3AE4C2D0)
 - [Udemy – MATLAB/SIMULINK Bible|Go From Zero to Hero!](https://www.udemy.com/course/matlabsimulink-biblego-from-zero-to-hero/)
 
+_________________
+
 ### Debugging
 
 #### JTAG / SWD
@@ -545,6 +685,8 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 
 - [This Is 100% How You Should Be Debugging | How to Use OpenOCD to Debug Embedded Software with GDB](https://www.youtube.com/watch?v=_1u7IOnivnM)
 
+_________________
+
 ### Testing
 
 - [Test Driven Development for Embedded C - James Grenning](https://www.amazon.com/Driven-Development-Embedded-Pragmatic-Programmers/dp/193435662X)
@@ -552,15 +694,21 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 
 #### Unit Testing
 
+- [Unit Testing for C (especially Embedded Software)](http://www.throwtheswitch.org/unity)
 - [Embedded C/C++ Unit Testing with Mocks](https://interrupt.memfault.com/blog/unit-test-mocking)
 - [Unit Testing Principles, Practices, and Patterns - Vladimir Khorikov](https://www.manning.com/books/unit-testing)
 
 #### Integration Testing
 
+- [Hardware CI Arena](https://electricui.com/blog/hardware-testing)
+- [https://www.bunniestudios.com/blog/?p=5450](https://www.bunniestudios.com/blog/?p=5450)
+
 #### SIL / HIL Testing
 
 - [Embedded CI/CD with HIL Testing](https://youtube.com/playlist?list=PL4cGeWgaBTe1uwiqIAc6fwPzPpvgPZI2J)
 
+_________________
+
 ### Embedded AI
 
 #### AI/ML Basics
@@ -581,10 +729,16 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [TinyML: Getting Started with TensorFlow Lite for Microcontrollers | Digi-Key Electronics](https://youtu.be/gDFWCxrJruQ)
 - [TinyML: Getting Started with STM32 X-CUBE-AI | Digi-Key Electronics](https://youtu.be/crJcDqIUbP4)
 
+_________________
+
 ### Embedded Security
 
 #### Cryptography
 
+- [Hashing, Hashing Algorithms, and Collisions - Cryptography - Practical TLS](https://youtu.be/HHQ2QP_upGM)
+- [Data Integrity - How Hashing is used to ensure data isn't modified - HMAC - Cryptography](https://www.youtube.com/watch?v=doN3lzzNEIM)
+- [Encryption - Symmetric Encryption vs Asymmetric Encryption - Cryptography - Practical TLS](https://www.youtube.com/watch?v=o_g-M7UBqI8)
+- [Public and Private Keys - Signatures & Key Exchanges - Cryptography - Practical TLS](https://youtu.be/_zyKvPvh808)
 - [Understanding AES Encryption Mechanics: BMPS](https://youtu.be/OnhtzFJW_4I)
 - [Understanding Cryptography: A Textbook for Students and Practitioners -  Christof Paar, Jan Pelzl](https://link.springer.com/book/10.1007/978-3-642-04101-3)
 - [Cryptography and Network Security: Principles and Practice - William Stallings](https://www.pearson.com/en-us/subject-catalog/p/cryptography-and-network-security-principles-and-practice/P200000003477/9780135764213)
@@ -598,12 +752,9 @@ PlatformIO is a cross-platform, cross-architecture, multiple framework, professi
 - [MOOC - Security Part4 : STM32 security in practice](https://youtube.com/playlist?list=PLnMKNibPkDnF0wt-ZI74SflnsBV4yKzkO)
 - [MOOC - Security Part5 : How to define your security needs](https://youtube.com/playlist?list=PLnMKNibPkDnGqh5OmQWw98ztpf9TeczbC)
 - [MOOC - Security Part6: STM32 security ecosystem, from theory to practice](https://youtube.com/playlist?list=PLnMKNibPkDnGd7J7fV7tr-4xIBwkNfD--)
-
-
-### SOFT SKILLS
-
-- [Soft Skills For Embedded Systems Software Developers](https://www.embeddedrelated.com/showarticle/1470.php)
-- [10 Skills Every Embedded Engineer Should Have](https://medium.com/@lanceharvieruntime/10-skills-every-embedded-engineer-should-have-dcb867095b91)
+- [TPM (Trusted Platform Module) - Computerphile](https://www.youtube.com/watch?v=RW2zHvVO09g)
+- [Securing Embedded Linux Systems with TPM 2.0 - Philip Tricca, Intel](https://www.youtube.com/watch?v=0qu9R7Tlw9o)
+- [TPM: Basic applications to embedded devices](https://witekio.com/blog/tpm-basic-applications-to-embedded-devices/)
 
 ## History
 
@@ -624,6 +775,6 @@ Special thanks to my friends in the community of Iranian Embedded Engineers in T
 
 ## Contribution
 
-If you think that this map can be improved in anyway, please start an issue or pull request. I’ll be maintaining and updating this repository frequently.
+If you think that this roadmap can be improved in anyway or you know some good learning resources that can be added here, please start an issue or a pull request. I’ll be maintaining and updating this repository frequently.
 
 The source file is created using [Microsoft Visio](https://office.com/visio) in `.vsdx` format and included in this repository for your contributions. If you do not have Microsoft Visio or you want to use free software, you can use [draw.io](https://draw.io) which can import and export `.vsdx` files.